- of or during the day.；(of animals) active in the daytime.
- 1. of or during the day. 同義詞
- ▪ (of animals) active in the daytime.
- ▪ (of flowers) open only during the day.
- 2. daily; of each day diurnal rhythms 同義詞
- ▪ of or resulting from the daily rotation of the earth diurnal aberration